(2) Although undefended places themselves are exempt, nevertheless military works, military or naval establishments, depôts of arms or war material, workshops or plant which could be utilised for the needs of the hostile fleet or army, and men-of-war in the harbour of undefended places may be bombarded. And no responsibility is incurred for any unavoidable damage caused thereby to the undefended place or its inhabitants. As a rule, however, the commander must, before resorting to bombardment of these works, ships, and the like, give warning to the local authorities so that they can destroy the works and vessels themselves. Only if, for military reasons, immediate action is necessary and no delay can be allowed to the enemy, may bombardment be resorted to without previous warning, the commander being compelled to take all due measures in order that the undefended place itself may suffer as little harm as possible (article 2). The first case in which naval forces acted according to these rules occurred during the Turco-Italian war. On February 25, 1912, Admiral Faravelli, the commander of an Italian squadron, surprised, at dawn, the Turkish gunboat _Awni-Illa_ and a torpedo-boat in the port of Beirut. These vessels were called upon to surrender, they were given until nine o'clock a.m. to comply with the demand, and the demand was communicated to the Governor and the Consular authorities. At nine o'clock the Turkish vessels were again, by signal, summoned to surrender, and as no reply was received, they were fired at and destroyed, but not without first having vigorously answered the fire of the Italians. Shells missing the vessels and bursting on the quay killed and wounded a number of individuals and damaged several buildings. The Turkish Government protested against this procedure as a violation of Convention IX. of the Second Peace Conference, but, provided the official report of Admiral Faravelli corresponds with the facts, the Turkish protest is unfounded. (3) In case undefended places do not comply with legitimate requisitions, they likewise may be bombarded; see details above, § 212. (4) In case of bombardments, all necessary steps must be taken to spare buildings devoted to public worship, art, science, or charitable purposes; historical monuments; hospitals, and places where the sick or wounded are collected, provided they are not at the time used for military purposes. To enable the attacking force to carry out this injunction, the privileged buildings, monuments, and places must be indicated by visible signs, which shall consist of large stiff rectangular panels, divided diagonally into two coloured triangular portions, the upper portion black, the lower portion white (article 5). Unless military exigencies render it impossible the commander of an attacking naval force must, before commencing the bombardment, do all in his power to warn the authorities (article 6).